Method of separating impurities from oxidised flow of dump

FIELD: process engineering.

SUBSTANCE: invention relates to removal of impurities and mother solution and wash filtrate extraction from oxidising reactor discharge flow formed in synthesis of carboxylic acid, usually, terephthalic acid. Proposed method comprises: (a) directing oxidised flow in zone of enrichment by solid particles to settle solid particles and form dumping flow suspension via cooling it, adding settling agent, removing solvent or combining said cooling and adding; (b) separating dumping flow suspension in separation zone to form filter pad and mother solution and forced flushing of said filter pad at high pressure in said separation zone by flushing fluid flow comprising water and, not obligatorily, solvent to form washed pad. Note here that said separation zone comprises at least one filter device operated at pressure and comprising at least one filter cell. Note also that said filter cell accumulates layer of filter pad with depth of at least 0.635 cm (0.25 inch), "c" directing at least a portion of flushing filtrate and at least a portion of mother solution to oxidising zone.

EFFECT: higher efficiency.

44 cl, 4 dwg

 

The SCOPE of the INVENTION

This invention relates to the removal of impurities and removing the mother liquor and wash filtrate from the oxidized stream discharge produced in the synthesis of carboxylic acid, typically terephthalic acid, and then to the subsequent direction of at least part of the mother liquor and/or washing of the filtrate back into the oxidation zone comprising at least one oxidation reactor.

BACKGROUND of INVENTION

Terephthalic acid is produced in industry by oxidation of paraxylene in the presence of a catalyst, such as, for example, Co, Mn, Br, and solvent. Terephthalic acid is used in the manufacture of polyester fibers, films and resins and must be further processed to remove impurities formed in the oxidation of paraxylene.

Terephthalic acid (TPA) is an intermediate product in the production of polyesters for use in plastics and fibers. An example of a method of production of TPA is shown in figure 1. Industrial methods of production of TPA are often based on catalyzed by heavy metals the oxidation of paraxylene, usually with bromidum promoter in a solvent is acetic acid, or a combination of these substances, known as the reaction mixture 405. Due to the limited solubility of TPA in acetic acid at practically the x oxidizing conditions usually formed in the reaction zone 400, which contains at least one oxidation reactor, usually formed suspension of crystals of TPA. Usually the suspension TPA 410 oxidation reactor is withdrawn from oxidation zone 400, and then the solid TPA can be separated from the oxidized mother liquor 415 in the separation zone 430 solid-liquid using conventional methods of separation of solid-liquid. The mother solution of the oxidizing agent 415, which contains most of the catalyst and promoter used in the method, return to the cycle in the oxidized zone 400, comprising at least one reactor. In addition to the catalyst and promoter of the mother solution of the oxidizing agent 415 also contains dissolved TPA and many by-products and impurities. These by-products and impurities arise partly from minor impurities present in the stream paraxylylene raw materials. Other impurities arise from incomplete oxidation of paraxylene, resulting in formation of products of partial oxidation. The oxidation of paraxylene to terephthalic acid are formed and other by-products as a result of competing side reactions. In U.S. patent 4158738 and 3996271 described obtaining terephthalic acid, which is incorporated by reference in their entirety to the extent that does not contradict stated here.

Solid the TPA may be subjected to separation of solid-liquid when using fresh solvent 420 in order to displace the main part of the liquid component stock solution of oxidizing agent 415. After drying, the solid TPA particles contaminated with impurities that were present in the mother solution of the oxidizing agent 415, since these impurities can be incorporated into solid particles of TPA.

Impurities are also present due to occlusion in the crystal structure of TPA and due to incomplete removal of the mother liquor oxidant 415 washing with fresh solvent 420.

Many of the impurities in the stream of mother liquor oxidant 415, which return in the cycle, are relatively inert to further oxidation. Such impurities include, for example, isophthalic acid, phthalic acid and trimellitic acid. There are also impurities, which can undergo further oxidation, such as, for example, 4-carboxybenzene, p-toluene acid and p-tolualdehyde. Inert to oxidation impurities tend to accumulate in the mother solution of the oxidizing agent 415 during recirculation. The concentration of these inert impurities in the mother solution of the oxidizing agent 415 will increase until, until equilibrium is reached at which the rate of removal of each impurity from the product TFA is balanced with the rate of formation and the rate of accumulation in the CA process is comprehension. Normal levels of impurities in technical terephthalic acid makes it unsuitable for direct use in most applications for polymers.

Typically terephthalic acid cleaned or conversion into dimethyl ether, or by dissolving in water with subsequent hydrogenation of the standard hydrogenation catalysts. In the last time to receive TPA polymer condition use secondary oxidation processing. It is desirable to minimize the concentration of impurities in the mother solution, and thereby to facilitate subsequent purification of TPA. In some cases it is impossible to obtain purified TPA polymer condition, if not use some means of removing impurities from the mother liquor oxidant 415.

One method of removing impurities from the recycle stream, widely used in chemical engineering, is the selection or removal of some part of the recirculating mother liquor oxidant 415. Usually fault (exhaust) flow only wound drains, but if it is economically justified, is subjected to various treatments to remove unwanted impurities, removing at the same time valuable components. One example is U.S. patent 4939297, incorporated by reference in its entirety to the extent that does not contradict stated here. The number is on allotment, required for pollution control, is dependent on the method, however, exhaust the number equal to 10-40% of the total flow of recirculating the mother liquor oxidant 415, called hereafter the oxidized stream 101 is reset, is usually sufficient to obtain TPA, suitable as raw material for the industrial production of polymers. However, in carrying out the invention can be used exhaust amount to 100%.

In the production of TPA, the percentage removal of the fallopian oxidizer solution 415 needed to maintain acceptable concentrations of impurities, in combination with the economic value of the metal catalyst and components of the solvent in the oxidized stream 101 reset makes the simple removal of the oxidized stream 101 reset economically disadvantageous. Thus, there is a need in the way in which derive the main part of precious metal catalysts and acetic acid contained in the oxidized stream 101 is reset, at the same time removing most of the impurities present in the oxidized stream 101 is reset. The metal catalyst may be recovered in active form suitable for re-use, direct return to the stage of oxidation of p-xylene.

In the invention it is proposed to extract the wash filtrate 148 and the mother liquor 47 of oxidized sweat the ka 101 reset. The oxidized stream 101 reset is sent to the separation zone and then the mother solution and/or wash the filtrate is returned to the oxidation reactor. It should be noted that the above method of TPA is only an example. The described invention can be applied in many different ways TPA, which produce the oxidized stream 101 is reset. Therefore, it should be noted that this invention is applicable not only to a method of producing terephthalic acid, but in any way, which produce the oxidized stream 101 reset, requiring the extraction of the mother liquor 147 and the wash filtrate 148 that includes a metal catalyst.

The INVENTION

This invention relates to the removal of impurities and removing at least part of the mother liquor and wash filtrate from the oxidized stream reset formed during the synthesis of carboxylic acid, typically terephthalic acid.

The present invention is the provision of a method of removing impurities and extraction of the mother liquor and wash filtrate from the oxidized stream reset.

Another objective of this invention is the provision of a method of removing impurities and extraction of the mother liquor and wash filtrate from the oxidized stream reset formed during the synthesis of carboxylic acid, and the direction is at least part of the mother liquor and/or washing of the filtrate in the zone of oxidation.

In the first embodiment of the present invention the method includes:

(a) the direction of oxidized stream discharge in the area of concentration of solid particles to form a slurry stream reset;

(b) separation of the suspension flow discharge into the separation zone for receiving the washed pellet, the mother liquor and wash filtrate;

(c) the direction of at least part of the wash filtrate and at least part of the mother liquor in the zone of oxidation.

In another embodiment of the present invention the method includes:

(a) adding a precipitating agent to the oxidized stream discharge in the area of concentration of solid particles to form a slurry stream reset;

(b) separation of the suspension flow discharge into the separation zone for receiving the washed pellet, the mother liquor and wash filtrate;

(c) the direction of at least part of the wash filtrate and at least part of the mother liquor in the zone of oxidation.

In another embodiment of the present invention the method includes:

(a) cooling the oxidized stream discharge in the area of concentration of solid particles to form a slurry stream reset;

(b) separation of the suspension flow discharge into the separation zone for receiving the washed pellet, the mother liquor and wash filtrate;

(c) at least cha is ti leaching effluent and at least part of the mother liquor in the zone of oxidation.

According to one variant embodiment of the invention, a method for removal of impurities and the metal catalyst from the oxidized stream discharge, representing the mother liquor obtained after separation of the solid aromatic carboxylic acid formed from the oxidation zone of the suspension aromatic carboxylic acid, and containing an aromatic carboxylic acid, water, a solvent, by-products, metal catalyst and impurities, including:

(a) the direction of oxidized stream discharge in the area of concentration of solid particles for deposition of solid particles with the formation of the suspension stream reset by cooling the suspension flow discharge, adding precipitating agent, solvent removal, or a combination of cooling and adding a precipitating agent,

(b) separation of the suspension flow discharge into the separation zone for the formation of filter cake and mother liquor and pressure washing the specified filter pellet under high pressure in said separation zone by the flow of drilling fluid comprising water and optional solvent, to form a washed pellet and wash filtrate, where the separation zone includes at least one filtering device, working under pressure, comprising at least one filter is Chaku, at least one filter cell accumulates a layer of filter cakes depth of at least 0,635 cm (0.25 inch),

(C) at least part of the wash filtrate and at least part of the mother liquor in the zone of oxidation.

Preferably fed to the rinsing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

Preferably the filtering device under pressure operates at a temperature between about 25°and about 160°C.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 5 ATM.

Preferably the dehydration leads to the formation of dehydrated cakes, having a moisture content from about 10% to about 50%.

Preferably the filtering device under pressure is a rotary drum filter working under pressure.

Preferably, the washing is counter-current.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

According to another variant of the invention, the claimed method of removing impurities and a metal catalyst from the oxidized stream discharge, representing the mother liquor obtained after separation of the solid is th aromatic acid formed from the oxidation zone of the suspension aromatic carboxylic acid, and containing an aromatic carboxylic acid, water, a solvent, by-products, metal catalyst and impurities, including:

(a) adding a precipitating agent to the oxidized stream discharge in the area of concentration of solid particles for deposition of solid particles with the formation of the suspension stream reset

(b) separation of the suspension flow discharge into the separation zone for the formation of filter cake and mother liquor and pressure washing the specified filter pellet under high pressure in said separation zone by the flow of drilling fluid comprising water and optional solvent, to form a washed pellet and wash filtrate, where the separation zone includes at least one filtering device, working under pressure, comprising at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0,635 cm (0.25 inch),

(c) the direction of at least part of the wash filtrate and at least part of the mother liquor in the zone of oxidation.

Preferably fed to the rinsing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

Preferably the filtering device under working pressure p and a temperature between about 25°and about 160°C.

Preferably, stage (C) includes placing at least 10% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

Preferably, stage (C) includes placing at least 50% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

Preferably the filtering device under pressure is a rotary drum filter working under pressure.

Preferably, the washing is counter-current.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

Preferably at least 25% by weight of the wash filtrate and at least 25% by weight of the mother liquor is sent to the zone of oxidation.

Preferably, the separation zone comprises at least one device for filtering under pressure.

Preferably the device for filtration under pressure includes at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0.25 inches.

Preferably fed to the rinsing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

Preferably the filtering device under d is the working pressure at a temperature between about 25°and about 160°C.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

Preferably, stage (C) includes placing at least 50% by weight of the wash filtrate and at least 50% by weight of the mother liquor in the zone of oxidation.

Preferably the filtering device under pressure is a rotary drum filter working under pressure.

Preferably, the washing is counter-current.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

According to another variant of the invention, the claimed method of removing impurities and a metal catalyst from the oxidized stream discharge, representing the mother liquor obtained after separation of the solid aromatic acid formed from the oxidation zone of the suspension aromatic carboxylic acid, and containing an aromatic carboxylic acid, water, a solvent, by-products, metal catalyst and impurities, including:

(a) cooling the oxidized stream discharge in the area of concentration of solid particles for deposition of solid particles with the formation of the suspension stream reset

(b) separation of the suspension flow discharge into the separation zone for the formation of filter cakes and fallopian what about the solution and pressure washing the specified filter pellet under high pressure in a specified area of separation of flow of washing fluid, comprising water and optional solvent, to form a washed pellet and wash filtrate, where the separation zone includes at least one filtering device, working under pressure, comprising at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0,635 cm (0.25 inch),

(C) at least part of the wash filtrate and at least part of the mother liquor in the zone of oxidation.

Preferably fed to the rinsing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

Preferably the filtering device under pressure operates at a temperature between about 25°and about 160°C.

Preferably, stage (C) includes placing at least 10% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

Preferably, stage (C) includes placing at least 50% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

Preferably the filtering device under pressure is a rotary drum filter working under pressure.

Preferably, the washing is counter-current.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

Preferably at least 25% by weight of the wash filtrate and at least 25% by weight of the mother liquor is sent to the zone of oxidation.

Preferably, the separation zone comprises at least one device for filtering under pressure, a pressure from about 1 ATM to about 50 ATM.

Preferably the device for filtration under pressure includes at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0.25 inches.

Preferably fed to the rinsing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

Preferably the filtering device under pressure operates at a temperature between about 25°and about 160°C.

Preferably the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

Preferably, stage (C) includes placing at least 50% by weight of the wash filtrate and at least 50% by weight of the mother liquor in the zone of oxidation.

Preferably the filtering device under pressure is a rotary drum filter working under pressure.

Preferably, the washing is counter-current.

Preferably the device is istwo filtration under pressure operates under a pressure from about 1 ATM to about 50 ATM.

These objectives and other objectives will become more understandable to specialists after reading this description.

BRIEF DESCRIPTION of DRAWINGS

1 shows a diagram of the method of production of TPA, where at least part of the combined wash filtrate 148 and/or mother liquor 147 return in recycling in the oxidation zone 400 on line 154.

Figure 2 shows the scheme of the method occurring in the separation zone 151, which form the mother liquor 147 and the wash filtrate 148, and then the part of the mother liquor 147 and/or wash filtrate 148 sent to the oxidation zone comprising at least one oxidation reactor.

Figure 3 shows another variant embodiment of the invention, where the suspension 110 stream reset is sent to the separation zone, including the filtration area 153, the zone of leaching 155 and the optional drying zone 157.

Figure 4 shows another variant embodiment of the invention, where the device for filtering method uses a rotary drum filter, working under pressure, with a rotary drum filter, working under pressure, includes an area of 153 filtering zone 155 flushing, optional zone 157 dehydration zone 164 and unloading zone leaching 162 tissue.

DETAILED description of the INVENTION

In one embodiment of the present invention offer the h method of removing impurities and extraction of the mother liquor 147 and the wash filtrate 148 of the oxidized stream 101 reset, which is shown in Fig.1-4. General reference positions on the drawings indicate the same product streams. The method includes the following steps.

The oxidized stream 101 reset removed from the way of oxidative synthesis of carboxylic acids. The oxidized stream 101 is reset by a thread supply for the present method. The oxidized stream 101 reset includes carboxylic acid, water, a solvent, a metal catalyst and at least one impurity. Impurities include at least one impurity selected from the group consisting of organic bromides, metal corrosion by-products of the oxidation of p-xylene and impurities formed from impurities in p-xylene.

Organic bromides can be used as promoters in oxidation reactions. Examples of metals corrosion are compounds of iron and chromium, which inhibit, reduce or completely destroy the activity of the metal catalyst. In addition to the catalyst and promoter of the flow of the mother liquor oxidant 415 also contains by-products and impurities. These by-products and impurities partially formed from minor impurities present in the stream of initial p-xylene. Other impurities are formed due to incomplete oxidation of p-xylene, resulting in partially oxidized products. Other by-products are financial p is tatom competing side reactions in the oxidation of p-xylene to terephthalic acid.

Carboxylic acid include aromatic carboxylic acids, obtained by controlled oxidation of organic bases. Such aromatic carboxylic acids include compounds with at least one carbonisation group attached to the carbon atom that is part of an aromatic ring, preferably having at least 6 carbon atoms, more preferably having only carbon atoms. Suitable examples of such aromatic rings include, but are not limited to, benzene, biphenylene, terpinolene, naphthalene and other condensed aromatic ring carbon based. Examples of suitable carboxylic acids include, but are not limited to, terephthalic acid, benzoic acid, p-Truelove acid, isophthalic acid, trimellitic acid, naphthaleneboronic acid, 2,5-diphenylethanol acid and mixtures thereof.

Suitable solvents include, but are not limited to, aliphatic monocarboxylic acids, preferably containing from 2 to about 6 carbon atoms, or benzoic acid and mixtures thereof and mixtures of these compounds with water. Preferably the solvent is acetic acid, mixed with water in a ratio of about 5:1 to about 25:1, preferably between about 8:1 and about 20:1. In PR is the future description of acetic acid is called a solvent.

However, it should be clear that can also be used in other suitable solvents, such as described previously.

Stage (a) includes the direction of oxidized stream 101 is reset to the zone of concentration of solid particles 140 to form a suspension 110 stream reset.

In one embodiment of the invention, the area of concentration of solid particles 140 includes apparatus suitable for making possible the cooling of the oxidized stream 101 is reset for the formation of a suspension 110 stream reset. This apparatus is not subject to special requirements except that it should provide sufficient time for cooling the oxidized stream 101 is reset to the desired temperature for the formation of a suspension 110 stream reset. This can be accomplished, for example, by using a vessel with stirring with cooling coil, or the use of various known in the art of heat exchangers. Area enrichment 140 solid particles may include any known in the art, the device is sufficient to cool the oxidized stream 101 reset sufficient to form a suspension 110 stream reset oxidation reactor, where the oxidized stream 101 reset would be chilled from at least 5°C up to at least 90°C. the Amount of cooling should depend on the desired values of the deposition. For example, the oxidized stream 101 reset can be cooled by at least 5°C. that is a temperature difference in degrees Celsius between the oxidized stream 101 is reset and the suspension 110 stream reset. Other intervals may be at least 10°C., at least 15°, at least 20°C., at least 25°C., at least 30°C., at least 35°C., at least 40°C., at least 45°C., at least 50°C., at least 55°C., at least 60°C., at least 65°C., at least 70°C for at least 75°With at least 80°C., at least 85°C. and at least 90°C. In another embodiment of the invention the oxidized stream 101 is reset at a temperature of from about 80°to about 150°C. Another interval is an interval from about 80°to about 140°C, and another interval is an interval from about 85°to about 100°C.

In another embodiment, the oxidized stream 101 reset served in the area of concentration of solid particles 140 to cause the precipitation of the solid particles of the oxidized stream 101 is reset. The deposition may be any known in the art methods. One way, for example, is adding to the outlet of the oxidation reactor flow precipitating agent 105. The precipitating agent 105 is introduced into a zone of concentration of solid particles 140 and causes the precipitation of the TV is rdih particles of oxidized stream 101 is reset. The precipitating agent 105 includes any compound that is suitable for the deposition of solid particles from the oxidized stream 101 is reset. Suitable compounds include, but are not limited to, water, methanol, isopropanol, n-butanol and Isobutanol. Other precipitating agents which may be used are C1-C6-allylacetate, such as, but not limited to this, n-propyl, isopropylacetate, isobutyl acetate, sec-butyl acetate, ethyl acetate, water and n-butyl acetate.

In another embodiment of the invention for stage (a) oxidized stream 101 reset concentrated by removal of acetic acid. Concentration carried out by any known in the practice of the method. This is carried out by boiling acetic acid to such an extent that wasn't enough acetic acid solvent to keep the dissolved solids in solution. Other means of solvent removal is the use of cross-flow membranes that allow passage of acetic acid through the membrane as permeate, resulting in the concentration of retentate.

In another embodiment of the invention for stage (a) solid particles generated in the zone of concentration of solid particles of any combination of cooling and adding a precipitating agent.

In other options, the ante embodiment of the invention the amount of solid particles in the process of concentration of solid particles may result in suspension 110 stream reset having at least 1% of the mass. up to at least 30% of the mass. solid particles. Another interval is the interval from at least 1% of the mass. to at least 25% of the mass. solid particles, and another interval is the interval from at least 1% of the mass. to at least 20% of the mass. solid particles. The enrichment of the solid particles may be carried out in the way described earlier cooling, or in another embodiment of the invention, the suspension 110 stream reset can be formed from the oxidized stream 101 is reset by using solvent evaporation. Evaporating apparatus may be such evaporation apparatus, as described in U.S. patent 4939297 or in patent applications U.S. 10/455016, 10/455018 and 10/874419, which is incorporated by reference to the extent that does not contradict stated here. In another embodiment, the invention can be any means known in the art up until achieve the desired solids content in the suspension 110 stream reset.

Stage (b) includes the separation of the suspension 110 of the flow discharge in the zone 151 separation for the formation of filter cakes 154 and the mother liquor 147, washing of filter cakes 154 flow of washing fluid 149 in the zone 151 separation for formation of the washed pellet 146 and the wash filtrate 148 and optional Obispo is of the washed pellet 146 in the area of 151 division for education dehydrated cakes 159, this area 151 separation includes at least one filtering device under pressure.

In another embodiment of the invention, the suspension 110 stream reset injected into the zone 151 separation where the separation zone includes an area of 153 filtering zone 155 washing and optional zone 157 drying, as shown in figure 3. Area 153 filtering includes filtering the cell or the number of filter cells, which are physically located so as to allow the filter cake to be distributed on the surface of the filter cells to delay or prevent kanalizirovanija drilling fluid 149 through the filter cake 154.

The filter cake 154 at least 0.25 inches to a depth of approximately 8 inches in depth, preferably at least 0.5 inches in depth, more preferably at least 1 inch in depth and even more preferably from about 2 to about 4 inches in depth distributed over the surface of the filtration cell. The washed pellet 146 may be removed or further processed, recycled and/or directed in the installation of waste treatment.

After reaching a suitable or preferred height of the filter cakes 154 from about 0.5 inch to about 4 inches of filter cake 154 leaves the area 153 filter that has a filter or R is d filters, and enters an area of 155 flushing, where the filter cake is in contact with the washing liquid 149. There is a sufficient pressure drop through filter cake 154 in order to provide a reservoir or accumulation of raw materials for washing on top of the filter cakes 154 to reach a suitable depth, preferably the minimum depth in 0,635 cm (0.25 inch). The pressure gradient in the filter cake 154 at least 3,447 kPa (0.5 psi (abs.)), preferably from about 34,47 kPa (5 psi) to about 448,16 kPa (65 psi) and a reservoir of washing fluid 149 can be used to displace any dissolved substance in the filter cake 154 flushing fluid 149.

The depth of the filter cakes 154 at least 1.27 cm (0.5 inch) is suitable for receiving the filter cakes 154 sufficient density to download a flushing means, i.e. it is such a filter cake 154 from which the wash filtrate 148 containing the dissolved substance from the filter cakes 154, can be effectively removed pressure washing. If the depth of the filter cakes 154 less than about 0,635 cm (0.25 inch), may be kanalizirovanija drilling fluid 149 in the filter 154, leading to uneven washing the filter Lepe is key 154.

Because of the loss of efficiency pressure washing of filter cakes 154 is preferred minimum depth of filter cakes purified terephthalic acid 154 at least 0,635 cm (0.25 inch).

In order to place pressure washing, required minimum height of the liquid layer above the surface of the filter cakes 154. This height should be sufficient to ensure that the surface of the filter cakes are completely covered with wash liquid 149. If the surface of the filter cakes is not covered by circulating fluid 149 may be vipasyana drilling fluid 149 without sufficient displacement of the dissolved substance in the filter cake 154. Because of the unevenness of the surface of the filter cakes 154 preferred minimum height of approximately 0,635 cm (0.25 inch) above the surface of the filter cakes 154.

It was found that the displacement of dissolved solids from the filter cakes 154 using drilling fluid 149 high pressure allows for efficient separation of the catalyst metals from the filter cakes 154. Another advantage of high pressure is to reduce the amount of washing fluid 149 required for the extraction of cobalt, as shown in the examples.

P is the physical alteration of an additional step in the separation zone 151 may reduce the amount of washing fluid 149, required to reduce the total amount of metal catalyst held in the filter cake 154. Therefore, a suitable number of stages of forced displacement washing must be used in order to minimize the total quantity of washing fluid 149 used in pressure washing, to reduce the load on the subsequent installation of waste processing.

It is clear that the operation of the multistage pressure washing can replace operation single-stage pressure leaching, where the number of washing fluid 149 sufficient to obtain at least 80% recovery of the metal catalyst from the suspension 110 of the flow discharge in the mother liquor 147 and the wash filtrate 148. Advanced operation using the several stages of counter-current rinsing, can be useful, if it is determined that the reduction in the number of circulating fluid 149 should be beneficial.

In the method according to the present invention, the suspension 110 stream reset administered in one or several rows of filtration cells, which are physically located so as to provide the possibility of formation of filter cakes 154 of the required thickness.

After reaching the minimum height of the filter cakes 154 about 0,635 cm (0.25 inch) filter cake 154 leaves Phi is ltr or a number of filters and enters the zone 155 flushing, where the filter cake 154 washed with the washing liquid 149. Then flush fluid 149 can be applied pressure in order to displace the dissolved substance filter cakes 154 (i.e. liquid and any dissolved compounds such as the metal catalyst in the filter cake). After displacement of the solute flushing fluid filter cake can be discharged from the zone 155 filtering by any suitable means and the cycle repeats. In carrying out the invention the ratio of washing liquid to 149 discharged filter cake is in the range from about 1:20 to about 20:1 in order to reduce the concentration of metal catalyst in the filter cake more than 95%.

Equipment for carrying out the desired wash cycle may include a number of filter cells held in the position appropriate to enable flow of washing fluid 149 to spread on top of the filter cells. In one embodiment of the invention suitable equipment can include a rotary drum filter, working under pressure with multiple filter cells, provided with a device for discharging the washed pellet 146 of the filter cells. The filter cake 154 may be p is washed so many times, how much is required in order to achieve a minimum concentration of metal catalyst in the washed pellet 146 before discharging the washed pellet 146 of the rotary drum filter.

A suitable filter under pressure, which can be adapted to the requirements of the method according to the present invention, is working under pressure rotary drum filter BHS-FEST™, BHS-WERK, Sonthofen, D-8972, Sonthofen, West Germany, although there may be used other pressure filters that can perform the desired operation. Examples of other devices that may be used in the area of 151 separation of solid-liquid include, but are not limited to working under pressure belt filters, filter presses, centrifuges, pressure leaf filters and cross-specific filters. Working under pressure filter can operate at a temperature and pressure sufficient to achieve at least 80% recovery of the metal catalyst from the solute mother liquor 147. Preferably working under pressure filter can operate at a temperature of from about 25°to about 160°C. and a pressure of from 1 ATM to 50 ATM.

When filter BHS-FEST™, as shown in figure 4, the rotary drum has a series of filter cells located at the periphery in which sausages drum. When the drum rotates, the filter cells take the suspension 110 stream reset and the filter cake 154 increases to the desired depth. The mother liquor 147 is obtained by filtering the suspension 110 stream reset. After turning drum filter cake 154 included in the zone of leaching 155, where the filter cake 154 create a reservoir of washing fluid 149 to the required depth. Attached to the reservoir drilling fluid pressure forces water to pass through the filter cake 154 to displace the dissolved substance (solute metal catalyst), held in suspension 110 stream reset to get the washed pellet 146. After the next rotation of the drum of the washing cycle may be repeated at least three times, if necessary, a counter-current manner, after which the pressure system is reset with concomitant lowering the temperature to ambient conditions.

The washed pellet 146 does not need to be dehydrated in the zone 157 dehydration steam supplied through line 152 to obtain a dehydrated cake 159 and wet steam 160. The resulting dehydrated cake 159 may then be unloaded from the drum by any known method.

Figure 4 shows a variant embodiment of the invention, where the device for the filtration process used in the n rotary drum filter, working under pressure. Rotary drum filter, working under pressure, includes an area of 153 filtering zone 155 flushing, optional zone 157 dehydration zone 164 and unloading zone 162 wash cloth. Area 164 discharge, shown in figure 4, refers to the variant in which a rotary drum filter, working under pressure, includes an area of 162 washing the tissue, where the filters are washed after unloading dehydrated cakes 159.

The wash filtrate 148 produced by pressure washing of filter cakes flushing fluid 149. The filter cake 154 in the zone 151 separation is subjected to extraction of the metal catalyst by entering the wash liquid 149 to form the wash filtrate 148, at least 80% of the metal catalyst is extracted in the wash filtrate 148 and the mother liquor 147. In one embodiment of the invention in the wash filtrate 148 and the mother liquor 147 derive at least 90% of the metal catalyst. The mother liquor 147 and the wash filtrate 148 can be optionally combined before exiting the zone 151 separation of solid-liquid.

The flush fluid 149 includes water and optionally additional solvent oxidation.

Perhaps most surprising was that when using water as promisec the second liquid 149 at temperatures in the range of from about 20°to about 70°C, preferably from about 30°to about 50°C., a sufficient amount of metal corrosion is delayed in the dehydrated cake 159, precluding the need to remove metal corrosion other means. Dehydrated cake 159, which represents the solid particles stripped from the metal catalyst can be withdrawn from the system.

It should be noted that the implementation of the invention uses in the zone 151 separation rotary drum filter, working under pressure, may include any known in the art device that is capable to obtain a mother liquor 147 and the wash filtrate 148 of the suspension 110 stream reset. For example, such devices may include, but are not limited to, a centrifuge, decanting centrifuge, batch-disc centrifuge, filters under pressure, such as filters, candle, leaf filters, filter press, etc.

Stage (C) includes placing at least part of the wash filtrate and/or at least part of the mother liquor in the zone of oxidation.

When carrying out the invention at least part of the mother liquor 147 and/or at least part of the wash filtrate 148 at the stage (s) can be returned to recycling in the oxidation zone is 400 comprising at least one oxidation reactor, in the process of obtaining terephthalic the th acid, including, but not limited to these, such as the process described in figure 1. At least a part can be any number greater than 1% of the mass. In another interval of at least a part can be any number, greater than 50 wt%. In another interval of at least a part can be any number, greater than 75% of the mass. In another interval of at least a portion may be 100% of the mass. Lines 152 and 153 represent that part, if it exists, the mother liquor 147 and the wash filtrate 148, respectively, which is not refundable in recycling in the oxidation zone 400. These threads can be used in other processes or destroyed by burning or other known in the art methods.

1. Method of removing impurities and a metal catalyst from the oxidized stream discharge, representing the mother liquor obtained after separation of the solid aromatic carboxylic acid formed from the oxidation zone of the suspension aromatic carboxylic acid, and containing an aromatic carboxylic acid, water, a solvent, by-products, metal catalyst and impurities, including:
(a) the direction of oxidized stream discharge in the area of concentration of solid particles for deposition of solid particles with the formation of the suspension stream reset by cooling the suspension thread sat the wasp, adding a precipitating agent, solvent removal, or a combination of cooling and adding a precipitating agent,
(b) separation of the suspension flow discharge into the separation zone for the formation of filter cake and mother liquor and pressure washing the specified filter pellet under high pressure in said separation zone by the flow of drilling fluid comprising water and optional solvent, to form a washed pellet and wash the filtrate, and the separation zone includes at least one filtering device, working under pressure, comprising at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0,635 cm (0.25 inch),
(C) at least part of the wash filtrate and at least part of the mother liquor in the zone of oxidation.

2. The method according to claim 1, which is supplied to the washing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

3. The method according to claim 2, in which the filtering device under pressure operates at a temperature between about 25°and about 160°C.

4. The method according to claim 3, in which the filtering device under the pressure of working under pressure from about 1 ATM to about 5 ATM.

5. With whom persons according to claim 4, in which dehydration leads to the formation of dehydrated cakes, having a moisture content from about 10% to about 50%.

6. The method according to claim 5, in which the filtering device under pressure is a rotary drum filter working under pressure.

7. The method according to any one of claims 1 to 6, in which the leaching is counter-current.

8. The method according to claims 1 to 6, in which the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

9. Method of removing impurities and a metal catalyst from the oxidized stream discharge, representing the mother liquor obtained after separation of the solid aromatic acid formed from the oxidation zone of the suspension aromatic carboxylic acid, and containing an aromatic carboxylic acid, water, a solvent, by-products, metal catalyst and impurities, including:
(a) adding a precipitating agent to the oxidized stream discharge in the area of concentration of solid particles for deposition of solid particles with the formation of the suspension stream reset
(b) separation of the suspension flow discharge into the separation zone for the formation of filter cake and mother liquor and pressure washing the specified filter pellet under high pressure in a specified area of separation of flow of washing fluid, VK is causa water and optional solvent, for the formation of the washed pellet and wash the filtrate, and the separation zone includes at least one filtering device, working under pressure, comprising at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0,635 cm (0.25 inch),
(c) the direction of at least part of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

10. The method according to claim 9, which is supplied to the washing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

11. The method according to claim 10, in which the filtering device under pressure operates at a temperature between about 25°and about 160°C.

12. The method according to claim 9, in which stage (C) includes placing at least 10% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

13. The method according to claim 9, in which stage (C) includes placing at least 50% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

14. The method according to claim 9 or 13, in which the filtering device under pressure is a rotary drum filter working under pressure.

15. The method according to claim 9 or 13, in which the leaching is counter-current.

17. The method according to claim 9, in which at least 25% by weight of the wash filtrate and at least 25% by weight of the mother liquor is sent to the zone of oxidation.

18. The method according to 17, in which the separation zone includes at least one device for filtering under pressure.

19. The method according to p, in which a device for filtering under pressure includes at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0.25 inches.

20. The method according to claim 19, which is supplied to the washing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

21. The method according to claim 20, in which the filtering device under pressure operates at a temperature between about 25°and about 160°C.

22. The method according to item 21, in which the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

23. The method according to item 22, in which stage (C) includes placing at least 50% by weight of the wash filtrate and at least 50% by weight of the mother liquor in the zone of oxidation.

24. The method according to 17, or 23, in which the filtering device under pressure is rotation the th drum filter, working under pressure.

25. The method according to any of PP or 23, in which the leaching is counter-current.

26. The method according to 17, in which the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

27. Method of removing impurities and a metal catalyst from the oxidized stream discharge, representing the mother liquor obtained after separation of the solid aromatic acid formed from the oxidation zone of the suspension aromatic carboxylic acid, and containing an aromatic carboxylic acid, water, a solvent, by-products, metal catalyst and impurities, including:
(a) cooling the oxidized stream discharge in the area of concentration of solid particles for deposition of solid particles with the formation of the suspension stream reset
(b) separation of the suspension flow discharge into the separation zone for the formation of filter cake and mother liquor and pressure washing the specified filter pellet under high pressure in said separation zone by the flow of drilling fluid comprising water and optional solvent, to form a washed pellet and wash filtrate, where the separation zone includes at least one filtering device, working under pressure, comprising at least one filter ACAC is, at least one filter cell accumulates a layer of filter cakes depth of at least 0,635 cm (0.25 inch),
(c) the direction of at least part of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

28. The method according to item 27, which is supplied to the washing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

29. The method according to p, in which the filtering device under pressure operates at a temperature between about 25°and about 160°C.

30. The method according to item 27, in which stage (C) includes placing at least 10% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

31. The method according to item 27, in which stage (C) includes placing at least 50% by weight of the wash filtrate or at least part of the mother liquor in the zone of oxidation.

32. The method according to item 27 or 31, in which the filtering device under pressure is a rotary drum filter working under pressure.

33. The method according to item 27 or 31, in which leaching is counter-current.

34. The method according to item 27, in which the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

35. The method according to item 27, in which at least 25% by weight of the wash filtrate and less is th least 25% by weight of the mother liquor is sent to the zone of oxidation.

36. The method according to item 27, in which the separation zone includes at least one device for filtering under pressure, a pressure from about 1 ATM to about 50 ATM.

37. The method according to p, in which a device for filtering under pressure includes at least one filter cell, and at least one filter cell accumulates a layer of filter cakes depth of at least 0.25 inches.

38. The method according to clause 37, which is supplied to the washing liquid forms a reservoir on top of the filter cake, which has a depth of at least 0.25 inches.

39. The method according to § 38, in which the filtering device under pressure operates at a temperature between about 25°and about 160°C.

40. The method according to § 39, in which the filtering device under the pressure of working under pressure from about 1 ATM to about 50 ATM.

41. The method according to p, in which stage (C) includes placing at least 50% by weight of the wash filtrate and at least 50% by weight of the mother liquor in the zone of oxidation.

42. The method according to p or 41, in which the filtering device under pressure is a rotary drum filter working under pressure.

43. The method according to p or 41, in which the leaching is counter-current.

44. The method according to p, in which the filtering device under the pressure of working under pressure about is about 1 ATM to about 50 ATM.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing highly pure terephthalic acid which involves the following steps: (a) an oxidation reaction, where p-xylene is oxidised in an acetic acid solution in the presence of a catalyst to form terephthalic acid, (b) obtaining crystals of crude terephthalic acid, where the suspension containing the precipitate of the obtained terephthalic acid is separated into a solid phase and a liquid to obtain crystals of crude terephthalic acid, (c) hydrogenation step, where crystals of crude terephthalic acid are dissolved in water to form an aqueous solution which is hydrogenated, (d) crystallisation of highly pure terephthalic acid, where terephthalic acid is crystallised from the hydrogenated aqueous solution to form a suspension of highly pure terephthalic acid, (e) obtaining crystals of highly pure terephthalic acid, where the suspension of highly pure terephthalic acid is separated into a solid phase and a liquid to obtain crystals of highly pure terephthalic acid and a primary mother solution, and (f) extraction of p-toluic acid from the primary mother solution and taking it to the oxidation reaction step, where the p-toluic acid extraction step includes the following steps: (I) adsorption step, where primary or secondary mother solution, obtained by cooling the primary mother solution in order to separate the solid phase and liquid, is fed in form of treated liquid into an adsorption column filled with an adsorption agent, where the p-toluic acid breakthrough time is greater than that of benzoic acid, for adsorption of p-toluic acid and benzoic acid from the treated liquid on the adsorption agent, (II) cutting supply of the treated liquid into the adsorption column for at a certain moment in time when concentration of benzoic acid in the effluent from the adsorption column reaches at least 10% of the concentration of benzoic acid in the treated liquid, (III) desorption step, where a desorption agent in form of acetic acid, methylacetate or their mixture is fed into the adsorption column for desorption of the adsorbed p-toluic acid and (IV) circulation step, where p-toluic acid contained in the desorption agent flows from the adsorption column and taken to the oxidation reaction step.

EFFECT: design of a method of obtaining highly pure terephthalic acid through selective extraction of p-toluic acid from waste water currently released, and use of the waste water as raw material for producing terephthalic acid.

19 cl, 6 dwg, 5 ex, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and a reactor-type bubble column. A stream of oxidising agent which contains molecular oxygen and a stream of starting material containing the oxidised compound are fed into the reaction zone of the bubble column reactor. As a result of oxidation, a solid-phase product from at least approximately 10 wt % of the oxidised compound is obtained. At least a portion of the reaction medium containing the solid-phase product is taken from the reaction zone through one or more openings lying at a higher level than the inlet zone of at least a portion of the molecular oxygen into the reaction zone. Average gas flow rate per unit cross section of the stream at half the height of the said reaction medium is kept equal to at least approximately 0.3 m/s. The proposed installation has a bubble column reactor with a perforated shell, a reaction medium container and a channel designed for carrying spent reaction medium into the container.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

32 cl, 35 dwg, 7 tbl, 13 ex

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and to the obtained crude terephthalic acid. Oxidation is carried out in a bubble column reactor which ensures a highly efficient process at relatively low temperature. Particles of the obtained terephthalic acid, which contains approximately less than 100 parts weight/million of 2,6-dicarboxyfluorenone, have transmission factor at 340 nm (%T340) greater than approximately 25%, additionally contains approximately less than 12 parts weight/million of 4,4-dicarboxystilbene and/or contains approximately less than 400 parts weight/million of isophthalic acid. Particles of the obtained terephthalic acid, characterised by average size ranging from approximately 20 to approximately 150 micrometres, are dissolved in tetrahydrofuran for one minute to concentration of a least approximately 500 parts/million and/or is characterised by average BET surface area greater than approximately 0.6 m2/g.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

37 cl, 36 dwg, 5 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method involves, for example: (a) evaporation of said oxidised discharge stream, containing terephthalic acid, metallic catalyst, impurities, water and solvent, in the first zone of an evaporator to obtain a vapour stream and a concentrated suspension of the discharge stream; and (b) evaporation of the said concentrated suspension of the discharge stream in the second zone of the evaporator to obtain a stream rich in solvent and a high-concentration suspension of the discharge stream, where the said second zone of the evaporator has an evaporator operating at temperature ranging from 20°C to 70°C, where from 75 to 99 wt % of the said solvent and water is removed by evaporation from the said oxidised discharge stream at step (a) and (b); (c) the said high-concentration suspension of the discharge stream is filtered in a zone for separating solid products and liquid to form a filtered product and a mother liquid; (d) washing the said filtered product using washing substances fed into the said zone for separating solid products and liquid to form a washed filtered product and washing filtrate; and dehydration of the said filtered product in the said zone for separating solid products and liquid to form a dehydrated filtered product; where the said zone for separating solid products and liquid has at least one pressure filtration device, where the said pressure filtration device works at pressure ranging from 1 atmosphere to 50 atmospheres; (e) mixing water and optionally extractive solvent with the said mother liquid and with all of the said washing filtrate or its portion in the mixing zone to form an aqueous mixture; (f) bringing the extractive solvent into contact with the said aqueous mixture in the extraction zone to form a stream of extract and a purified stream, where the said metallic catalyst is extracted from the said purified stream.

EFFECT: improved method of extracting metallic catalyst from an oxidised discharge stream obtained during production of terephthalic acid.

36 cl, 3 dwg, 2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing a dry residue of aromatic dicarboxylic acid containing 8-14 carbon atoms, suitable for use as starting material for synthesis of polyester, where the said method involves the following sequence of stages, for example: (a) oxidation of aromatic material in the oxidation zone to obtain a suspension of carboxylic acid; (b) removal of impurities from the suspension of aromatic dicarboxylic acid in the liquid-phase mass-transfer zone where at least 5% liquid is removed, with formation of a residue or suspension of aromatic dicarboxylic acid, and a stream of mother solution, where the liquid-phase mass-transfer zone includes a device for separating solid substance and liquid; (c) removal of residual impurities from the suspension or residue of aromatic dicarboxylic acid obtained at stage (b) in the zone for countercurrent washing with a solvent to obtain a residue of aromatic dicarboxylic acid with the solvent and a stream of mother solution together with the solvent, where the number of steps for countercurrent washing ranges from 1 to 8, and the countercurrent washing zone includes at least one device for separating solid substance and liquid, and the said solvent contains acetic acid, (d) removal of part of the solvent from the residue of aromatic dicarboxylic acid together with the solvent obtained at stage (c) in the zone for countercurrent washing with water to obtain a residue of aromatic dicarboxylic acid wetted with water and a stream of liquid by-products together with the solvent/water, where the number of countercurrent washing ranges from 1 to 8, and the countercurrent washing zone includes at least one device for separating solid substance and liquid, where stages (b), (c) and (d) are combined into a single liquid-phase mass-transfer zone, and directing the residue of aromatic dicarboxylic acid wetted with water directly to the next stage (e), (e) drying the said residue of aromatic dicarboxylic acid wetted with water in the drying zone to obtain the said dry residue of aromatic dicarboxylic acid suitable for synthesis of polyester, where the said residue wetted with water retains the form of residue between stages (d) and (e).

EFFECT: design of an improved version of the method of preparing dry residue of aromatic dicarboxylic acid.

21 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a continuous stepped counterflow method of catalytic oxidation in a solvent of at least one benzene compound, containing two substituting groups, which are selected from alkyl, hydroxyalkyl, aldehyde, carboxyl groups and their mixtures, which can be oxidised to the corresponding acid derivative, involving the following steps: (a) introducing a mixture of material into the first oxidation step, containing at least part of the total amount of each of: (i) solvent, which is an organic acid, (ii) at least one catalytically active metal, selected from manganese, cobalt, nickel, zirconium, hafnium, cerium and their mixtures, and (iii) bromine in molar ratio, in terms of all catalytically active metals, in the interval from 1:20 to 5:1 and from 7 to 60 wt % of the total amount of at least one disubstituted benzene, introduced at steps (a) and (d); (b) partial oxidation of at least one disubstituted benzene at the first oxidation step in the presence of a gas, containing molecular oxygen initially in amount of 3 to 20 vol. %, at temperature ranging from 121°C to 205°C and relative quantities of disubstituted benzene, catalytic metal, solvent and bromine, introduced at step (a), so that from 25 to 99.95 wt % disubstituted benzene, added at the first oxidation step, is oxidised with formation of a gaseous mixture, containing unreacted molecular oxygen, evaporated solvent and a first mixture of products, containing acid derivative, partially oxidised disubstituted benzene, unreacted disubstituted benzene and solvent, and at pressure from 8.96·105 to 14.8·105 Pa, sufficient for keeping disubstituted benzene, partially oxidised disubstituted benzene, acid derivative and solvent in liquid state or in form of a suspension of solid substance in a liquid, so that concentration of residual molecular oxygen in the remaining gaseous mixture ranges from 0.3 to 2 vol. %; (c) extraction of the obtained first product mixture after the first oxidation step and supplying at least part of the extracted first product mixture to the second oxidation step; (d) supplying gas to the second oxidation step, containing molecular oxygen and residue form total amount of disubstituted benzene, catalytic metal, solvent and bromine; (e) oxidation at the second oxidation step of partially oxidised disubstituted benzene and unreacted disubstituted benzene, supplied to the second oxidation step, with a gas containing molecular oxygen in amount of 15 to 50 vol. %, at temperature ranging from 175°C to 216°C and relative quantities of disubstituted benzene, partially oxidised disubstituted benzene, catalytic metal, solvent and bromine, introduced at step (a), so that from 96 to 100 wt % disubstituted benzene and partially oxidised disubstituted benzene is oxidised with formation of a gaseous mixture, which contains unreacted molecular oxygen, evaporated solvent and a second product mixture, containing acid derivative and solvent, and at pressure from 11.7·105 to 16.2·105 Pa so as to keep the acid derivative, partially oxidised disubstituted benzene and unreacted disubstituted benzene mainly in liquid state or in form of a suspension of solid substance in a liquid, so that concentration of residual molecular oxygen in the remaining gaseous mixture ranges from 3 to 15 vol. %; (f) extraction after the second oxidation step of the second product mixture, containing acid derivative; and (g) tapping gas which contains residual molecular oxygen after the second oxidation step and returning it to the first oxidation step.

EFFECT: method allows for maximum use of oxygen without reducing quality of the desired carboxylic acid using a stepped counterflow oxidation system.

25 cl, 11 tbl, 29 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention refers to the improved method for oxidising of aromatic hydrocarbon such as para-xylol, meta-xylol, 2,6-dimethylnaphthalene or pseudocumene with forming of corresponding organic acid. The oxidation is implemented by the source of molecular oxygen in liquid phase at temperature range from 50°C to 250°C in the presence of catalyst being a) oxidation catalyst based on at least one heavy metal representing cobalt and one or more additive metals being selected from manganese, cerium, zirconium, titanium, vanadium, molybdenum, nickel and hafnium; b) bromine source; and c) unsubstituted polycyclic aromatic hydrocarbon. The invention refers also to the catalytic system for obtaining of organic acid by the liquid-phase oxidation of aromatic hydrocarbons representing: a) oxidation catalyst based on at least one heavy metal representing cobalt and one or more additive metals being selected from manganese, cerium, zirconium, titanium, vanadium, molybdenum, nickel and hafnium; b) bromine source; and c) unsubstituted polycyclic aromatic hydrocarbon.

EFFECT: activation of the aromatic hydrocarbons oxidation increasing the yield of target products and allowing to decrease the catalyst concentration and the temperature of the process.

45 cl, 4 tbl, 16 ex

FIELD: chemistry.

SUBSTANCE: method of obtaining product - purified carboxylic acid, includes: (a) oxidation of aromatic initial materials in primary oxidation zone with formation of raw carboxylic acid suspension; where raw carboxylic acid suspension contains terephthalic acid; where said oxidation is carried out at temperature within the range from 120°C to 200°C; (b) withdrawal of admixtures from raw suspension of carboxylic acid, removed at temperature from 140°C to 170°C from stage of oxidation of paraxylol in primary oxidation zone and containing terephthalic acid, catalyst, acetic acid and admixtures, realised in zone of solid products and liquid separation with formation of mother liquid flow and product in form of suspension; where part of said catalyst in said suspension of raw carboxylic acid is removed in said mother liquid flow; and where into said zone of solid products and liquid separation optionally additional solvent is added; (c) oxidation of said product in form of suspension in zone of further oxidation with formation of product of further oxidation; where said oxidation is carried out at temperature within the range from 190°C to 280°C; and where said oxidation takes place in said zone of further oxidation at temperature higher than in said primary oxidation zone; (d) crystallisation of said product of further oxidation in crystallisation zone with formation of crystallised product in form of suspension; (e) cooling of said crystallised product in form of suspension in cooling zone with formation of cooled suspension of purified carboxylic acid; and (i) filtration and optionally drying of said cooled suspension of purified carboxylic acid in filtration and drying zone in order to remove part of solvent from said cooled suspension of carboxylic acid with obtaining of said product - purified carboxylic acid.

EFFECT: purified carboxylic acid with nice colour and low level of admixtures, without using stages of purification like hydration.

8 cl, 1 tbl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention pertains to improved method of lowering content of 4-carboxybenzoldehyde and p-toluic acid in benzenedicarboxylic acid, which is terephtalic acid. Method involves: (1) supplying (i) p-xylene (ii) water acetic acid reaction medium, containing oxidation catalyst, containing source of cobalt, manganese and bromine source, dissolved in it, and (iii) acid containing gas in the first oxidation zone at high pressure, in which there is liquid phase, exothermal oxidation of p-xylene. In the first reactor, oxidation at high temperature and pressure is maintained at 150-165°C and 3.5-13 bars respectively; (2) removal from the upper part of the first reactor of vapour, containing water vapour, acetic acid reaction medium and oxygen depleted gas, and directing the vapour into the column for removing water; (3) removal from the lower part of the column for removing water of liquid, containing partially dehydrated acetic acid solution; (4) removal from the lower part of the first reactor of the oxidation product, containing (i) solid and dissolved terephtalic acid, 4-carboxybenzaldehyde and p-toluic acid, (ii) water acetic acid reaction medium, containing oxidation catalyst dissolved in it; (5) supplying (i) product of oxidation from stage (4), (ii) oxygen containing gas and (iii) solvent in vapour form, containing acetic acid, obtained from a portion of partially dehydrated acetic acid solvent from stage (3) into the second oxidation zone high pressure, in which there is liquid phase exothermal oxidation of 4-carboxybenzaldehyde and p-toluic acid, where temperature and pressure in the second reactor of oxidation at high pressure is maintained at 185-230°C and 4.5-18.3 bars respectively; (6) removal from the upper part of the second reactor of vapour, containing water vapour, acetic acid reaction medium, and oxygen depleted gas; (7) removal from the lower part of the second reactor of the product of second oxidation, containing (i) solid and dissolved terephtalic acid and (ii) water acetic acid reaction medium; and (8) separation of terephtalic acid from (ii) water acetic acid reaction medium from stage (7) with obtaining of terephtalic acid. The invention also relates to methods of obtaining terephtalic acid (versions). The obtained product is terephtalic acid, with an overall concentration of 4-carboxybenzaldehyde and p-toluic acid of 150 ppm or less.

EFFECT: improved method of lowering content of 4-carboxybenzoldehyde and p-toluic acid in benzenedicarboxylic acid and obtaining terephtalic acid.

13 cl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention pertains to improved method of lowering content of 4-carboxybenzoldehyde and p-toluic acid in benzenedicarboxylic acid, which is terephtalic acid. Method involves: (1) supplying (i) p-xylene (ii) water acetic acid reaction medium, containing oxidation catalyst, containing source of cobalt, manganese and bromine source, dissolved in it, and (iii) acid containing gas in the first oxidation zone at high pressure, in which there is liquid phase, exothermal oxidation of p-xylene. In the first reactor, oxidation at high temperature and pressure is maintained at 150-165°C and 3.5-13 bars respectively; (2) removal from the upper part of the first reactor of vapour, containing water vapour, acetic acid reaction medium and oxygen depleted gas, and directing the vapour into the column for removing water; (3) removal from the lower part of the column for removing water of liquid, containing partially dehydrated acetic acid solution; (4) removal from the lower part of the first reactor of the oxidation product, containing (i) solid and dissolved terephtalic acid, 4-carboxybenzaldehyde and p-toluic acid, (ii) water acetic acid reaction medium, containing oxidation catalyst dissolved in it; (5) supplying (i) product of oxidation from stage (4), (ii) oxygen containing gas and (iii) solvent in vapour form, containing acetic acid, obtained from a portion of partially dehydrated acetic acid solvent from stage (3) into the second oxidation zone high pressure, in which there is liquid phase exothermal oxidation of 4-carboxybenzaldehyde and p-toluic acid, where temperature and pressure in the second reactor of oxidation at high pressure is maintained at 185-230°C and 4.5-18.3 bars respectively; (6) removal from the upper part of the second reactor of vapour, containing water vapour, acetic acid reaction medium, and oxygen depleted gas; (7) removal from the lower part of the second reactor of the product of second oxidation, containing (i) solid and dissolved terephtalic acid and (ii) water acetic acid reaction medium; and (8) separation of terephtalic acid from (ii) water acetic acid reaction medium from stage (7) with obtaining of terephtalic acid. The invention also relates to methods of obtaining terephtalic acid (versions). The obtained product is terephtalic acid, with an overall concentration of 4-carboxybenzaldehyde and p-toluic acid of 150 ppm or less.

EFFECT: improved method of lowering content of 4-carboxybenzoldehyde and p-toluic acid in benzenedicarboxylic acid and obtaining terephtalic acid.

13 cl, 1 dwg, 1 ex

The invention relates to a method for the isomers of phthalic acid with a high degree of purity of the three-stage liquid-phase oxidation of xylene isomers, which improves the efficiency of the process and to improve the quality of the target product through the application of new catalytic systems that can improve the response speed limiting stages, namely, the conversion speed isomers Truelove acid and carboxybenzaldehydes (KBA) in target products at moderate temperatures, as well as to achieve a rapid, almost instantaneous mixing of the reactants in the reaction zone with an ideal distribution in the reaction space of the nutrient mixture, which comes in the form of restricted flows (submerged in liquid jets) with a high degree (6-30 m/s) countercurrent with respect to the direction of the circular rotation of the reaction mixture

The invention relates to a method for isomers benzylcarbamoyl acid with a high degree of purity, and this method does not require the cleanup phase hydrogenation method

FIELD: chemistry, pharmacology.

SUBSTANCE: present invention relates to new use of compounds of 2-arylacetic acid and amides with formula (I) and their pharmaceutically used salts, where A comprises an atom X and is phenyl or a 5-6 member heteroaromatic ring, optionally containing a heteroatom, chosen from N; corresponding positions on ring A are marked by numbers 1 and 2; atom X is chosen from N (nitrogen) and C (carbon); R represents a substituting group on ring A, chosen from: a group in 3 (meta) positions, chosen from a group comprising straight or branched C1-C5-alkyl, C2-C5-acyl; a group in 4 (para) positions, chosen from a group, comprising C1-C5-alkyl, C1-C5-alkanesulphonylamino, substituted with halogens; Hy represents a small hydrophobic group with steric inhibition constant ν between 0.5 and 0.9 (where ν is Charton steric constant for substitutes), comprising methyl, ethyl, chlorine, bromine, group Y chosen from O (oxygen) and NH; when Y represents O (oxygen), R' represents H (hydrogen); when Y represents NH, R' is chosen from groups: -H, - residue with formula SO2Rd, where Rd represents C1-C6-alkyl. The invention can be used in making medicinal agents, which are inhibitors of induced IL-8 PMN chemotaxis (CXCR1) or induced GRO-α PMN chemotaxis (CXCR2).

EFFECT: new use of compounds of 2-arylacetic acid and amides and their pharmaceutically used salts.

14 cl, 2 tbl, 44 ex, 4 dwg

FIELD: chemistry.

SUBSTANCE: present invention pertains to new compounds with general formula (I), in which X1 is phenyl, 9-member bicyclic heteroaryl, containing S or O as heteroatoms, or 5-member heteroaryl, containing S or O as heteroatoms, each of which is optionally substituted with one or more substitutes, chosen from halogen or C1-6alkyl, which is optionally substituted with one or more halogens. X2 is phenyl, which is optionally substituted with one or more substitutes, chosen from halogen, or 5-member heteroaryl, containing S or O as heteroatoms. Ar is phenylene, which is optionally substituted with one or more substitutes, chosen from halogen, or C1-6alkyl, phenyl, C1-6alkoxy, each of which is optionally substituted with one or more halogens. Y1 is O or S, and Y2 represents O, Z represents -(CH2)n-, where n equals 1, 2 or 3. R1 is hydrogen or C1-6alkoxy and R2 is hydrogen, C1-6alkyl. The invention also relates to pharmaceutical salts of these compounds or any of their tautomeric forms, stereoisomers, stereoisomer mixtures, including racemic mixtures.

EFFECT: invention also pertains to use of these compounds as pharmaceutical compositions, with effect on receptors, activated by the peroxisome proliferator PPARδ subtype, and to pharmaceutical compositions, containing these compounds (I).

36 cl, 41 ex

FIELD: chemistry.

SUBSTANCE: claimed method of obtaining alkylaromatic monocarboxylic acids involves liquid phase oxidation of dialkyl-substituted aromatic hydrocarbons by oxygen-containing gas in the presence of catalyst at high temperature. Alkyltrimethylammonium bromide with alkyl C14-C16 or their mix at 0.3-0.5 wt % of hydrocarbon weight is used as catalyst. Process is performed at 90-120°C until mass ratio of alkylaromatic acid to alkylaromatic aldehyde in the mix reaches 1:1.3-3.0, then alkylaromatic acid is separated, and unreacted hydrocarbon and aldehyde are returned to the process.

EFFECT: possibility to perform mild partial oxidation of dialkyl-substituted aromatic hydrocarbons selectively by one alkyl group without adding transition metals.

2 cl, 8 ex

FIELD: reagent methods of cleaning waste printed circuit board pickling solutions from copper (II); chemical technology of organic agents.

SUBSTANCE: cleaning is performed by adding to waste solution reagent containing monocarbonic acid of aromatic series or its salt, or anhydride at subsequent forming of sediment of salt of copper (II) with anion of monocarbonic acid of aromatic series.

EFFECT: low cost of method; high purity.

19 cl, 1 tbl,, 7 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing aromatic carboxylic acid ammonium salts by reaction of aromatic carboxylic acid with ammonia in aprotonic solvent medium. Method involves carrying out the reaction in the closed vessel by continuous addition of aromatic carboxylic acid in aprotonic solvent medium and passing gaseous ammonia under condition providing maintenance of ammonia partial pressure in the range from 0.1 to 3 bars and elimination of ammonium salt suspension in aprotonic solvent. Method allows preparing ammonium salts as crystals of a definite size that exhibit narrow distribution by size.

EFFECT: improved preparing method.

9 cl, 1 dwg, 6 ex

The invention relates to the field of fine organic synthesis, particularly to a method of obtaining p-butylbenzoic acid

The invention relates to substituted benzoic acids, in particular to an improved method polucheniya p-oksibenzoynoy acid, which nahodiat used in the manufacture of dyes, pharmaceuticals, upon receipt of liquid-crystal compositions
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